Effect of Multi-sensory Stimulation on Neuromuscular Development of Premature Infants: A Randomized Clinical Trial.

Objectives Preterm birth is considered as a risk factor for developmental disabilities, which can lead to long-term effects on the nervous system of children. The aim of this study was to determine the effect of multi-sensory stimulation on neurodevelopment of premature infants. Materials and Methods In this two-group double-blind clinical trial in Jahrom Hospital, Jahrom, Iran from Jun to Aug 2016, 80 preterm infants were randomly divided. The intervention group received multisensory stimulation for 12 min per session, 5 sessions per wk along with routine NICU care and the control group received ward's routine care. Neuromuscular maturity for each infant was assessed by New Ballard Score. Data were analyzed using independent t-test. Results Based on ANOVA with repeated measures, New Ballard score significantly changed in the intervention group before and after intervention (P= 0.001). This change was also significant in the control group (P=0. 04). However, the changes in New Ballard score were significantly different before and after intervention between the two groups (P=0.001). Conclusion Multi-sensory stimulation can have beneficial effects on the development of neuromuscular in premature infants.


Introduction
According to WHO, the infants born earlier than 37 wk from the first day of last menstruation are considered premature infants and its prevalence is estimated as 5%-7% globally (1). Premature birth is the most common cause of infants' death considered as one of the risk factors developmental outcomes in premature infants admitted to the neonatal intensive care unit (8). Multi-sensory stimulation is relatively a new intervention closely related to principles of evolutionary care (9). Since 1960, different researchers have proposed different types of multi-sensory stimulation for premature infants admitted in the hospital with aim to simulate the intrauterine environment at the first weeks of life in order to maintain and facilitate the development of premature infants (10).
Different stimulation programs included auditory touch-motor or situational stimulation or visual stimulation (11). Sensory stimulation, either single or multi-sensory stimulation, had positive outcomes and results in the process of evolutionary domains (12). Now, there is contradictory evidence of the effect of multi-sensory stimulation from neuromuscular aspect in premature infants and short-term effects of multi-sensory stimulation (auditory, tactile, vestibular and visual stimulation) on neuromuscular development in premature infants have rarely been reported (9)(10)(11)(12).
The aim of this study was to determine the effect of multi-sensory stimulation on neuromuscular development of premature infants.

Materials and Methods
This two-group double-blind randomized clinical trial study was conducted from Jun to Aug 2016.
The studied population were preterm infants admitted to Jahrom Hospital, Jahrom central Iran who entered to the study based on information contained in the records.
This study was conducted with a confirmation ethics of Jahrom University of Medical Sciences (IRCT code: IRCT2016073114454N2). for developmental disabilities, which can lead to long-term complications in the nervous system of infants (2).
Following preterm birth, natural developmental processes are impaired, especially when the infant is born so early, which requires intensive care (3). They are at risk for developmental problems.
The causes of developmental problems are first, their premature birth may be due to pre-existing problems, second, birth in such premature pregnancy can cause damage to vital organs like heart and lungs, and third, this damage can occur during the neonatal period following treatment measures (4).
In addition, exhaustion caused by compliance or stress can also lead to injury or damage to development. Moreover, very stimulatory environment of the hospital and lack of social interaction experiences with mother and great interaction with others can add to the above risks.
Many reasons are conceivable that by itself or in interaction with other causes can lead to cause the problems related to the growth and development of premature infants. Often it is unclear how much premature infants are affected by these cases (5).
Although the brain of the infants born at 25 to 40 wk, is still immature but is rapidly evolving (6). Impairment of brain growth and development in the early stages can affect some basic structures formed during this course of brain development, but there still needs to further evolve (7). All neuro-motor capacities should more evolve to be prepared for functions that are more complex after infant's discharge from the hospital (6,7). Then, required explanation about the purpose of the study was given to the parents by the researcher as face-to-face.
If they tend to participate in the study, written In order to lack of bias in the results of the study, who measure to assess the neuromotor development of the preterm by using the New Ballard Scale was

Results
There was no significant difference between intervention and control groups in terms of gestational age, birth weight, height, length and head circumference and 1 st and 5 th min Apgar score; therefore, two groups are homogeneous in terms of this variable (P>0.05) ( Table 1). The results of variance analysis with repeated measurements showed that New Ballard score significantly changed in the intervention group before and after intervention (P=0.001). This change was also significant in the control group (P=0.04). However, the changes in New Ballard score were significantly different at before and after intervention between the two groups (P=0.001) (

Discussion
Due to the high cost of care for premature infants and their neurological and physiological problems, care after the birth of these infants has been considered by the researchers from last few decades to improve the living environment of these infants and effective and essential changes are Short-term effects of multisensory stimulation in  There was a positive association between infant neurologic development and massage with human/ social contact (18). "More recently, multisensory intervention in the form of play improved mental, motor, and social development in a group of children (age range of 6 months-2.5 yr) living in an orphanage in India" (19).
The limitations of this study were as follows: Duration of follow up in the current study was very short. In addition, the effect of any of the stimulation in infants did not determine, future studies be done in this regard as separated and their results are compared with one another.
In conclusion, high-risk infants, children and